SAN FRANCISCO, Jan. 10 (Xinhua) -- Fish and wildlife authorities of the U.S. western state of Oregon have begun killing predatory California sea lions to protect endangered salmon, local media reported on Thursday.
According to the Oregonian/OregonLive newspaper, at least four sea lions have been removed from the Willamette Falls and killed at a second location under a federal permit by Thursday morning, because the predatory aquatic mammals are threatening the winter run of rainbow trout that become steelhead when they swim back to the ocean.
Over the past decade, the paper said, a growing number of sea lions have been traveling more than 160 km upstream from the mouth of the Columbia River to Bonneville Dam and Willamette Falls south of Portland in Oregon, where they hunted for migrating salmon on their way to the streams where they hatched.
Officials of the Oregon Department of Fish and Wildlife (ODFW) are allowed to kill 93 California sea lions each year if they find sea lions are preying on salmon for two consecutive days.
A recent ODFW study showed that the sea lions were eating so many winter steelhead at the falls in one year that the trout risks a high rate of extinction.